Ubuntu 26.04 has a bug in their pc-kernel snap causing it not to ship firmware for some devices (like my iwlwifi chipset), and because it mounts read-only directories into /var/lib/firmware/ you can't install the updated firmwares from apt either. Unless you're willing to do something like unpack the .deb file manually and extract the relevant firmwares from it, your wifi card won't work.

This isn't an issue with the hardware being too new or anything; it all works and the firmwares are all available, but Ubuntu's kernel snaps don't ship them and they make it much harder to get them yourself either.